An AC motor driven by a frequency signal such as an alternating current can be broadly classified into two types; namely, a synchronous motor and an induction motor. A synchronous motor is a motor that rotates at the same rotational speed as the speed of the rotating magnetic field determined with the power supply frequency upon employing a laminated core of a permanent magnet or a ferromagnetic body such as iron as the rotor.
Depending on the type of rotor, there is a magnet type employing a permanent magnet, a coil type in which a coil is wound thereto, and a reactance type employing a ferromagnetic body such as iron. Among the above, with the magnet type, the permanent magnet of the rotor rotates by being pulled by the rotating magnetic field of the stator. Meanwhile, the induction motor is a motor that rotates by the conductor generating a separate magnetic field with the electromagnetic induction effect to the rotor shaped like a cage.
Among the foregoing motors, there are types that move linearly without rotating, or are able to move freely on the surface. These types of motors are generally referred to as linear motors, and, by linearly arranging the coil for generating a magnetic pole and sequentially switching the current to be flowed, the permanent magnet or ferromagnetic body mounted thereon will move. The coil arrangement disposed linearly corresponds to a stator, and a rotor corresponds to a flat slider that slides above such stator.
As the foregoing magnet type synchronous motor, for example, there is a miniature synchronous motor described in Japanese Patent Laid-Open Publication No. H8-51745 (Patent Document 1). As illustrated in FIG. 1 of Patent Document 1, this miniature synchronous motor is structured by comprising a stator core 6 to which an exciting coil 7 is wound, and a rotor 3 having a built-in magnet 1 and a rotor core 2 in which NS poles are disposed in equal intervals around the circumference thereof.
Nevertheless, with the motor explained in the conventional art, there is a problem in that the weight will increase in comparison to the generated torque, and the size thereof must be enlarged in order to generate greater torque. Thus, an object of the present invention is to provide a magnetic structure to be employed in a motor superior in torque and weight balance and suitable for miniaturization, a motor utilizing this structure, and a driving method of this magnetic structure. Another object of the present invention is to provide various drivers utilizing this motor.